Western Peru, in the upper Marañon River

The Marañon dry forests extend along the upper Marañon River valley and its tributaries in northwestern Peru. The dry climate is caused by a rain shadow effect from the mountains to the east. This small ecoregion of high biological importance is composed of tropical deciduous forest, and arid and riparian scrub. The region is an area of high bird endemism, with a total of 22 restricted-range species, 11 of which are endemic to this dry forest. The area has been affected by agriculture for many years. Other threats include cattle ranching and logging.

Scientific Code

(NT0223)

Ecoregion Category

Neotropical

Size

4,400 square miles

Status

Habitats

Description

Location and General Description

Biodiversity Features

Current Status

Types and Severity of Threats

Justification of Ecoregion DelineationThis dry inter-Andean valley separated the northern and southern Andes across northern Peru. This is one of the lowest point traversing the Andes and had been a primary dispersion route between the Pacific and Atlantic forests. Linework for this ecoregion follows Instituto Geográfico Nacional (1987), who classify this as "equatorial dry forest". We separated this valley from portions of similar dry classifications extending northwards due to expert opinion at a regional priority setting workshop (Bogota, Colombia, 24-26, July, 2000) and based on the uniqueness of the area; namely species endemism, as this dry valley is classified as an Endemic Bird Area (Stattersfield et al. 1998).